Much attention has been given to the flow applications of viscoelastic solutions generated from the micelles of surfactants and organic counterion additives.  However, there is little knowledge of what is actually occurring on the molecular level.  Our goal is to build a physical picture of the local environment of the various entities and how they move during flow.

NMR investigation of micellar materials under viscoelastic flow has the full range of observables, and the special advantage of being non-invasive and nondestructive.  NMR is a unique tool for measuring molecular dynamics on time scales from seconds to nanoseconds.  We have developed rotational imaging techniques for obtaining NMR spectra of sheared simple fluids in cylindrical Couette flow.  Spectra from layers of fluid moving at selected frequencies are obtained by the combination of stroboscopic pulse sampling and a spatially defined magnetic field gradient which rotates synchronously with the selected fluid layer.  Thus, we generate distribution information for flowing fluids in addition to the standard solution NMR data about molecular identity and concentration, and solution dynamics.  The method selects circular slices across the streamline flow.